Apparatus for making pipe or tubing



Dec. 3, 1940. J. ANDERSON APPARATUS FOR MAKING PIPE OR TUBING Filed July '17, 1936 INVENTOR Patented Dec. 3, 1940 UNITED STATES APPARATUS FOR MAKING PIPE OR TUBING James L. Anderson, Closter, N. J., assignor to Air Reduction Company, Incorporated, New York, N. Y., a corporation of New York Application July 17, 1936, Serial No. 91,212

4 Claims.

This invention relates to apparatus for making welded pipe or tubing.

In the manufacture of pipes or tubes by pulling flat skelp through forming and closing means 5 it is advantageous to use rolls rather than stationary dies for forming and closing the tube, be-

cause the rotation of the rolls permits the skelp to travel through the roll passes with substan-' tially no friction and a minimum of erosion.

10 In the case of stationary bells or dies there is considerable friction between the die and the surface of the skelp, particularly when the skelp is not highly heated and therefore has no liquor over its surface to serve as a lubricant. The

15 greater force required to bend the cooler skelp is another factor increasing its friction against the die. The friction between the unlubricated skelp and the stationary die causes the surface of the skelp to be scratched and gives the welded 2o tube an outside finish which is unacceptable to customers.

Although better results are obtained with rolls, it has not been advantageous to use them because the skelp is withdrawn from the fur- 25 nace by tongs and it has been diflicult to get the tongs into the roll passes. Mechanism for separating the rolls of the various passes to admit the tongs when starting each length of skelp adds complication to what is otherwise a simple and rugged apparatus.

' It is an object of this invention to provide an improved apparatus for withdrawing skelp from a furnace and for starting it through a mill having rolls for forming and closing the skelp to 35 make a tube, the term tube being used herein to mean either pipe or tubing. The invention obtains the advantages incident to the use of rolls in a plurality of stands and has most of the simplicity of stationary die apparatus.

Other objects, features and advantages of the invention will appear or be pointed out as the specification proceeds.

In the accompanying drawing, forming part hereof:

45 Fig. l is a plan view, partly in section, of forming and welding apparatus embodying the invention;

Fig. 2 is a side elevation, with the furnace in section, showing the apparatus of Fig. 1; and 50 Figs. 3-6 are sectional views taken on the lines 3-3 to 66, respectively, of Fig. 2, but showing the passage of the skelp through the roll passes and retort.

Fig. 4 is on an enlarged scale. 55 Strips of skelp II are heated in a furnace I2.

The tapered front end of each strip is bent up and has an opening I3 through which a hook I5 can be inserted to pull the skelp from the furnace. The hook I5 is at the end of a long rod I! which is used instead of tongs for withdrawing the skelp from the furnace. The rod II has a head I9 for engaging a dog 28 on the chain 2I. of a drawbench 22.

An opening through the skelp II is the simplest expedient for hooking the rod II to the 10 skelp, but equivalent plans can be used, such as a hooked end on the skelp or a transverse rib behind which the hook I5 can catch.

The first forming roll stand, or break-down pass through which the skelp I I travels, after being pulled from the furnace, includes a convex upper roll 25 and a concave lower roll. 26 which cooperate to bend the skelp I I to the form shown in Fig. 3. These rolls 25, 26 have their axles supported in fixed bearings 21, which may have the usual adjustments of a forming roll stand. The upper roll has a groove 28 in the center of its face. This groove is considerably deeper than the height of the rod I'I (shown in dotted lines in Fig. 3) so that the rod can not 2 only pass between the rolls 25 and 26 but can be moved up and down within a limited range before coming into contact with one of the rolls. This vertical movement permits the rod II to be manipulated sufiiciently to insert the hook I5 in the hole I3. The hook I5 may be inserted either upwardly or downwardly through the hole I3, but can be inserted somewhat more easily from the bottom.

A second forming pass includes two rolls 30 rotatable on parallel vertical axles and. shaped to bend the skelp into a horseshoe section. The skelp bent into this partially formed tube is indicated by the reference character II' in Fig. 4. The distance between the upper portions of the 40 rolls 30 is greater than the width of the rod I! so that these rolls do not interfere with up and down movement of the rod whenhooking it into the skelp. The rod I1 is shown in dotted lines in Fig. 4.

Beyond the rolls an the partially formed skelp passes through an edge-heating retort 32, the construction of which is shown in Fig. 5. A torch 33 directs flames against the edge faces of the partially formed skelp. Guide surfaces 35 inside of the retort have grooves 36 which permit the products of combustion to flow across the outside surface of the metal. These gases escape through exhaust slots 31 in the sides of the retort and through a bottom exhaust slot The space between the bottom of the guide 35 and the lower end of the torch 33 is more than the height of the rod l1, and it is possible, therefore, to move the rod within a limited vertical range with the. retort closed. In order to allow for greater vertical movement of the rod l1 when manipulating it to hook the skelp, the retort 32 is made in two parts, a fixed lower section 40 and an upper section 4| which is joined to the lower section by a hinge 43. This construction permits the retort to open into the dotted line position shown in Fig. 5. The torch 33 is carried by the upper section 4| so that when the retort is open the rod l1 can be moved vertically into and out of the retort without encountering any obstruction.

Rolls 46 and 41 complete the forming of the skelp into a tube by bringing the heated edges together to make a weld. These welding rolls may be adjusted to exert any desired pressure or no pressure on the meeting edges, depending upon the type of weld desired.

The upper roll 46 is movable toward and from the lower roll 41. Mechanism for moving the upper roll is shown diagrammatically in Fig. 6. The axle of the roll 46 is carried by a support 49 which can be rocked about a fixed pivot 50. A fluid motor 5| connected to the support 49 moves the support about its pivot 56 to move the upper roll 46 into and out of position for cooperation with the lower roll 41.

The operation of the invention will be described briefly. With the roll 46 raised and the retort 32 preferably open, the rod I1 is inserted through the pass between the first forming rolls 25 and 26 and into the furnace. The rod is manipulated to bring its end under a skelp II in position to insert the hook at the end of the rod through the opening I3 in the skelp. The rod 11, which may be at an incline when its hooked end catches the skelp, is then laid in the horizontal position. The rod is pulled toward the drawbench for a short distance if this is necessary to bring the end of the rod intov position to be caught by the next dog on the drawbench chain. The rod l1 shown in the drawing is long enough to extend over the drawbench chain without pullingthe rod forward after it is hooked to the skelp. In Figs. 1 and 2 the drawbench has already moved the rod and skelp for a short distance. v

7 After the rod I1 has been hooked to. the skelp and laid in a horizontal position extending between the rolls 30, through the retort 32, and across the lower welding roll 41, the retort 32 is closed and the motor 5| is operated to bring the upper roll 46 into the position in which it cooperates with the lower roll 41 to form the welding roll pass.

As the drawbench pulls the rod l1, the skelp is moved through the successive roll passes shown in Figs. 3 and 4, then through the retort as shown in Fig. 5', and finally through the welding roll pass of Fig. 6.

the skelp is initially heated to less than welding heat, a continuous forming mill in line with the furnace, said forming mill comprising a first roll stand in which skelp is partially formed as it is pulled from the furnace and one or more other roll stands including a welding roll stand in which the forming of the skelp is completed and the seam edges brought together to make a weld, a rod of substantially smaller cross-section than the pass defined by the rolls of the first roll stand when in working relation, said rod being of sufficient length to extend through both of said roll stands and reach a skelp in the furnace, a hook on the end of the rod for pulling the skelp from the furnace, apparatus for heating the skelp edges locally to a. welding temperature and means for causing the rod to advance through the roll in line with the furnace, said forming mill comprising a first roll stand in which skelp is partially formed as it is pulled from the furnace and one or more other roll stands including a welding roll stand in which the forming of the skelp is completed and the seam edges brought together to makea weld, a rod of sufiicient length to extend through the roll stands of the forming mill and reach a skelp in the furnace, said rod being of substantially smaller cross-section than the pass defined by the rolls of the first roll stand when in working relation, a hook on the end of the rod for pulling. the skelp from the furnace,

means for causing the rod to advance throughthe roll stands and pull the front end of the skelp through the forming mill, and retort apparatus between successive roll stands of the forming mill for heating the seam edges to a welding condition as the partially-formed tube travels toward the welding rolls.

3. Tube welding apparatus including in combination a furnace for heating skelp to substantially less than welding heat, a skelp-pulling tool comprising a rod on one end of which is a hook for catching the skelp to pull it from the furnace, forming rolls which remain in working relation with one another but when in such relation have clearance for the rod, a retort for heating the skelp to a welding temperature, and welding rolls that complete the forming and bring the skelp edges together, the hooked rod extending between the welding rolls, and through the retort and forming roll pass, when the retort and the forming rolls are in operative position, to engage a skelp in the furnace.

4. Tube welding apparatus including in combination a furnace for heating skelp to less than welding heat, a skelp-pulling tool comprising a rod on one end of which is a hook for catching the skelp to pull it from the furnace, forming rolls which in working relation with one another have.

clearance for the rod, local heating apparatus for and welding rolls that complete the forming and bring the skelp edges together, the hooked rod being of sufiicient length to reach between the -welding rolls, and past the local heating apparatus and forming roll pass, when the local heating apparatus and the forming rolls are in operative position, to engage a skelp in the furnace.

JAMES L. ANDERSON. 

